The Response to Oxidative DNA Damage in Neurons: Mechanisms and Disease

Figure 3

H₂O₂-induced DNA damage and repair as detected by γH2AX foci formation in neurons derived from different brain regions. (a) Left: percentage of cells bearing 10 or more γH2AX foci at different times after treatment with 20 μM H₂O₂ for 30 min. One-way ANOVA and post hoc analysis Least Significant Differences (LSD) indicated a significant increase of γH2AX positive cells immediately and 30 minutes after the treatment in all brain regions. Two-way ANOVA did not show any interaction between the treatment and the neuronal cell type. Right: kinetics of γH2AX dephosphorylation following posttreatment times up to 24 hrs. ANOVA test shows any interaction between treatment and the three types of neurons on slopes of focus kinetics. For each time point, at least 100 nuclei were examined. Error bars indicate standard error. versus untreated (NT) by LSD test; ^§ versus by LSD test; versus untreated (NT) by LSD test; ^§§ versus by LSD test; versus untreated (NT) by LSD test. (b) Immunofluorescence of γH2AX (red, Ser 139; Millipore, Billerica, MA, USA) in neurons exposed to H₂O₂ (20 μM, 30 min) with or without 1 hr pretreatment with a specific ATM kinase inhibitor KU55933 (10 μM). Nuclei are stained with DAPI in blue. One representative experiment is shown.

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